Recombinant Dengue 2 Virus NS3 Helicase Protein Enhances Antibody and T-Cell Response of Purified Inactivated Vaccine.

Dengue virus is purified inactivated vaccine (PIV) highly immunogenic and protective in the short term, but may be poor at inducing cell-mediated immune response and long-term protection. The dengue nonstructural protein 3 (NS3) is considered as the main target for T-cell responses during viral infection. 

The amino (N) -terminal protease and Horse Recombinant Proteins

 carboxy (C) -terminal helicase domain of NS3 DENV-2 was expressed in E. coli and analyzed for the capacity of the immune-potentiating them. Mice immunized with DENV-2 PIV with and without recombinant NS3 protease or helicase NS3 protein and NS3 protein alone at day 0, 14 and 28. 

NS3 helicase NS3 protease but not effective in stimulating T-cell response was measured by IFN -γ ELISPOT. In addition, the real increase in total IgG antibody titer against viral antigens seen in mice immunized with PIV combination helicase / NS3 in ELISA, as well as increased neutralizing antibody titers were measured by test plaque reduction neutralization. These results show the potential immunogenic properties of the NS3 helicase protein and its use in dengue vaccine formulation.

N-terminal processing of affinity-tagged recombinant proteins purified by IMAC procedures.

The ability of a new class of metal binding tag to facilitate the purification of recombinant proteins, exemplified by glutathione S-transferase tag and human growth hormone from Escherichia coli fermentation broths and lysates have been investigated further. containing histidine tag indicates a high affinity for the metal ion chelated with ligands immobilized limit, 1,4,7-triazacyclononane (TACN). 

The use of this TACN tag immobilized metal ion affinity chromatography (IMAC) systems pose a high selectivity associated with the removal of host cell proteins and permits smooth tag removal from recombinant proteins E. coli-expressed. In particular, this tag is specifically designed to enable their efficient removal by the dipeptidyl aminopeptidase 1 (DAP-1), thus capturing the benefits of high substrate specificity and the rate of cleavage. MALDI-TOF MS analysis of the product cleaved from the DAP-1 digestion of the recombinant protein N-terminal Native Recombinant Proteins

 tagged confirmed the complete removal of the tag within 4-12 hours under mild experimental conditions. 

Overall, this study demonstrates that the use of special tags designed to target TACN based IMAC resins offer a comprehensive and flexible approach to purification E